Table 1 Key characteristics of exposed and control pregnancies included in infection and vaccination analysesa

From: Neonatal and maternal outcomes following SARS-CoV-2 infection and COVID-19 vaccination: a population-based matched cohort study

 

Infected

Uninfected controls

Vaccinated

Unvaccinated controls

Number of pregnancies

4074

12222

11379

22758

Median maternal age (min–max)

29 (14–45)

29 (14–46)

32 (14–52)

31 (15–53)

Maternal deprivation

1 (most deprived)

1225 (30.1%)

3089 (25.3%)

1620 (14.2%)

4890 (21.5%)

2

1028 (25.2%)

2556 (20.9%)

1838 (16.2%)

4449 (19.5%)

3

681 (16.7%)

2295 (18.8%)

2138 (18.8%)

4196 (18.4%)

4

675 (16.6%)

2404 (19.7%)

2864 (25.2%)

5100 (22.4%)

5 (least deprived)

465 (11.4%)

1865 (15.3%)

2917 (25.6%)

4104 (18%)

Unknown/Missing

0 (0%)

13 (0.1%)

2 (<0.1%)

19 (0.1%)

Maternal ethnicity

White

3611 (88.6%)

10108 (82.7%)

9845 (86.5%)

18851 (82.8%)

South Asian

183 (4.5%)

383 (3.1%)

433 (3.8%)

825 (3.6%)

Black/Caribbean/African

57 (1.4%)

205 (1.7%)

132 (1.2%)

479 (2.1%)

Other/mixed ethnicity

156 (3.8%)

437 (3.6%)

468 (4.1%)

909 (4.0%)

Unknown/Missing

67 (1.6%)

1089 (8.9%)

501 (4.4%)

1694 (7.4%)

Maternal urban/rural status

Large urban areas

1616 (39.7%)

4136 (33.8%)

4369 (38.4%)

8219 (36.1%)

Other urban areas

1644 (40.4%)

4664 (38.2%)

3548 (31.2%)

8167 (35.9%)

Accessible small towns

248 (6.1%)

980 (8.0%)

961 (8.4%)

1842 (8.1%)

Remote small towns

89 (2.2%)

402 (3.3%)

346 (3.0%)

656 (2.9%)

Accessible rural areas

373 (9.2%)

1375 (11.3%)

1459 (12.8%)

2632 (11.6%)

Remote rural areas

81 (2.0%)

582 (4.8%)

601 (5.3%)

1073 (4.7%)

Unknown/Missing

23 (0.6%)

83 (0.7%)

95 (0.8%)

169 (0.7%)

Parity

0

1655 (40.6%)

5430 (44.4%)

4824 (42.4%)

8528 (37.5%)

1+

2298 (56.4%)

6435 (52.7%)

6164 (54.2%)

13512 (59.4%)

Unknown/missing

121 (3.0%)

357 (2.9%)

391 (3.4%)

718 (3.2%)

Maternal clinical vulnerability

Not clinically vulnerable

3012 (73.9%)

8698 (73.4%)

8411 (73.9%)

16680 (73.3%)

Clinically vulnerable

1035 (25.4%)

3141 (25.7%)

2839 (24.9%)

5879 (25.8%)

Extremely vulnerable

27 (0.7%)

113 (0.9%)

129 (1.1%)

199 (0.9%)

Maternal diabetes

No diabetes

3749 (92.0%)

11430 (93.5%)

10411 (91.5%)

20864 (91.7%)

Pre-existing diabetes

28 (0.7%)

108 (0.9%)

147 (1.3%)

182 (0.8%)

Gestational diabetes

297 (7.3%)

684 (5.6%)

821 (7.2%)

1712 (7.5%)

Maternal smoking status

Non-smoker

2785 (68.4%)

7976 (65.3%)

8612 (75.7%)

15548 (68.3%)

Ex-smoker

819 (20.1%)

2505 (20.5%)

2074 (18.2%)

4509 (19.8%)

Smoker

468 (11.5%)

1687 (13.8%)

679 (6.0%)

2638 (11.6%)

Unknown/Missing

2 ( < 0.1%)

54 (0.4%)

14 (0.1%)

63 (0.3%)

Body mass index

Underweight

90 (2.2%)

337 (2.8%)

176 (1.5%)

451 (2.0%)

Healthy weight

1411 (34.6%)

4701 (38.5%)

4324 (38%)

8422 (37.0%)

Overweight

1288 (31.6%)

3551 (29.1%)

3431 (30.2%)

7044 (31.0%)

Obese/severely obese

1203 (29.5%)

3304 (27.0%)

3183 (28%)

6298 (27.7%)

Unknown/Missing

82 (2.0%)

329 (2.7%)

265 (2.3%)

543 (2.4%)

  1. aThe data presented related to Cohort 1: singleton pregnancies ending in a live or stillbirth at ≥20 + 0 gestation used for analyses of stillbirth and extended perinatal death outcomes. The exposed pregnancies included in Cohorts 2–10 differed slightly from those in Cohort 1, and the controls were redrawn for each cohort. Characteristics of Cohorts 2–10 therefore differ from those shown above, although differences were minimal.
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